FLOOR DECK
SMD’s metal floor decking products are commonly used as part of a composite floor slab, where the decking acts as both permanent formwork and tensile reinforcement (sagging) in the bottom of the slab (basis of design in accordance with BS5950: Parts 4 & 6 or Eurocodes 3 and 4).
Alternatively, our decking profiles may be used as permanent formwork only. In this situation any reinforcement required to support the specified imposed loads is to be designed by the project structural engineer, ignoring any contribution from the metal decking.
All our profiles use steel strip in compliance with BS EN 10143 & BS EN 10346 with guaranteed minimum yield strengths of 350 and 450 N/mm2 and a minimum coating mass of 275g/m2.
r51+ floor deck
R51+ is a traditional re-entrant profile and is commonly used on inner city high multi-storey projects where the structural zone is limited, due to the relatively thin slab depth required to achieve a typical 1 hour fire rating.
Specification
- Available in 0.9mm, 1.0mm and 1.2mm gauges
- Manufactured from S350 and S450* grade galvanised steel
- Soffit service fixings available with 1 kN load capacity
TR60+ floor deck
TR60+ provides high span capabilities and increased steel efficiency at a competitive price. Due its 1.0m cover width, this profile can be installed quickly making it a popular choice for many design engineers. The typical 1 hour fire rating can be achieved with a 130mm slab.
Specification
- Available in 0.9mm, 1.0mm and 1.2mm gauges
- Manufactured from S350 and S450* grade galvanised steel
- Soffit service fixings available with 1 kN load capacity
TR80+ floor deck
LEWIS® METAL FLOOR DECK
The unique LEWIS® profile with its optimal geometry provides a combined action between the LEWIS® deck and the concrete/screed ensuring an extremely high load bearing capacity.
Specification
- Available in 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm gauges
- Manufactured from S320GD, Magnelis® Option available
- 580mm cover width, 16mm deep
SPECIFICATIONS
All SMD decks are manufactured from galvanised steel coil to BS EN 10346 with a standard 275g/m² coating which equates to 0.02mm (20μm) per face. Although the galvanising provides a protective coating, it does weather, albeit at approximately one tenth of the rate of bare steel (depending upon the prevailing conditions).
Useful references on the life to first maintenance (LTFM) of galvanised steel coil include:
- Galvanizers Association, “The Engineers and Architects Guide: Hot-dip Galvanizing”
- Corus Strip Products UK, “Protected with strength – Solutions in Galvatite hot-dip galvanised steel”
- The Steel Construction Institute, P262 – Durability of Light Steel Framing in Residential Building: Second Edition
- SCI Advisory Desk Note 247: Use of Composite Construction in an Aggressive Environment,” New Steel Construction, April 2010.
In summary, the above references conclude the LTFM for galvanised steel coil with a 20 μm coating as shown in Table 7.4a for the different corrosivity categories.
From Table 7.4a, it is apparent that identifying the corrosivity category for the design situation is key to obtaining an accurate life to first maintenance. The environment in which the material will be located must be carefully assessed to determine which of these categories is applicable for the location in question.
The LTFM figures presented in the table above are similar to those documented by the galvanised steel suppliers for the different locations (shown below):
Internal:
Dry & Unpolluted: 20 – 50 years
(Typical for most common applications – offices, warehouses, hospitals, airports)
External:
Suburban & Rural: 5 – 10 years
Coastal: 2 – 5 years
Industrial and Urban: 2 – 5 years
